Pneumatic sensing system



Dec. 3, 1968 c c, BELL ET AL PNEUMATIC SENSING SYSTEM Filed March 28,1967 TO SENSOR //v VEN 7'0/25, 6/4/2155 C BELL United States Patent3,413,794 PNEUMATIC SENSING SYSTEM Charles C. Bell, Warwick, and Kurt W.Niederer, Saunderstown, R.I., assignors to Leesona Corporation, Warwick,R.I., a corporation of Massachusetts Filed Mar. 28, 1967, Ser. No.626,502 Claims. (Cl. 57-80) ABSTRACT OF THE DISCLOSURE A pneumaticsensing system for sensing a yarn strand in a textile operation isdescribed. The system comprises in combination a yarn feeler, a 'vane,an air jet and air receiver, and a fluid pressure transducer. Theelements are constructed and arranged to continuously supply air to thetransducer as long as a yarn strand is present. In the absence of a yarnstrand, the vane, which is in operable association with the yarn feeler,will interrupt the air supply, exhausting the transducer, which willactivate a signal to stop a work cycle, or initiate a rethreadingprocedure. A preferred embodiment utilizes the improved pneumaticsensing system in an automatic spinning unit having a patroling tender.This embodiment employs a registration vane in operable association witha second air jet and air receiver. The registration vane interrupts thesecond air supply at each spinning station, but the transducer is notexhausted unless both air jets are interrupted. When the pneumatic yarnsensing system is employed on a patrolling spinning tender, it can becoordinated with a full bobbin sensor.

Field of invention This invention relates to textile equipment andmachinery. More particularly, the invention is directed to an improvedsensing system for the detection of a yarn strand in a textile operationwhich, in the absence of a yarn strand, will automatically stop a workcycle or initiate a rethreading operation.

Background and prior art Various textile operations are encountered inwhich a yarn strand is running, or fed from one position to another. Inautomatic equipment of the aforesaid type, it is necessary to detectwhen the yarn strand is broken or when a yarn threading operation hasnot been properly effected. Yarn sensors or feelers are thereforeemployed in automatic textile machinery which will actuate a mechanicalor electrical signal in the absence of a yarn strand. All of such yarnsensors, however, are limited in application. More specifically, most ifnot all textile operations are accompanied by an accumulation of lint,dust, oil, or the like. Accordingly, mechanical and electrical sensorscan become fouled and as a result may fail to actuate the requiredsignal. To offset the aforesaid, sensors have been developed which areextremely sensitive. The latter sensors are still not the completeanswer since, because of their extreme sensitivity, they are oftenactauted accidentally, inadvertently interrupting the sequence of thetextile operation.

Objects and brief description of invention Accordingly, it is an objectof the present invention to provide an improved yarn sensor for use withtextile 3,413,794 Patented Dec. 3, 1968 machinery which has extremelyhigh amplification, but is not critically sensitive to malfunctionvariables.

It is another object of this invention to provide an improved yarnsensor for use with textile machinery which substantially precludesfouling.

It is another object of this invention to provide an improved pneumaticyarn sensor for use with textile machinery.

It is another object of this invention to provide a pneumatic yarnsensing device which can be employed on a patroling tender in a spinningoperation which will detect the absence of a yarn strand at a spinningstation, stop the tender and initiate a rethreading operation.

It is still another object of this invention to provide a pneumatic yarnsensing system which can be employed on a patroling tender in a spinningoperation and comprises a yarn feeler and registration vane, whereby theyarn feeler will detect the absence of a yarn strand but will only stopthe tender and initiate a rethreading operation when the yarn strand isabsent at a spinning position.

It is still another object of this invention to provide an improvedpneumatic yarn sensing device for use wit-h an automatic spinning devicehaving a patrolling tender which can be coordinated with a full bobbinsensor.

These and other objects of the invention will be more readily apparentfrom the following detailed description with reference to the drawing.

The aforesaid objects of the present invention are realized byconstructing a sensor comprising a yarn feeler, a vane in operableassociation with said feeler, and an air jet and air receiver incommunication with a fluid pressure transducer. The sensor isconstructed and arranged to have the air jet supply air through the airreceiver to the transducer, provided a yarn strand is present. In theevent the yarn strand is absent, the vane in association with the feelerwill interrupt the air supply to the transducer causing the transducerto be exhausted and actuate an electrical signal, sounding an alarm,stopping the textile operation and/or initiating a rethreading of themachinery.

As a preferred embodiment, the improved sensing system is employed on apatrolling tender controlling an automatic spinning unit. In thisembodiment, a registration vane in association with a second air jet andreceiver is utilized. The registration vane is constructed to interruptthe second air supply at each spinning station. However, the transduceris not exhausted unless both air jets are interrupted. In the preferredembodiment, it is possible to coordinate the transducer of the yarnsensing system with a second operation such as a full bobbin sensingdevice. If this expediency is employed, a relatively high air pressureis maintained on a valve means. A full bobbin sensing finger isconstructed and arranged on the patrolling tender to actuate the valve,passing air to the side of the transducer opposite from that in contactwith the air receivers in communication with the yarn sensor, whichimmediately actuates the stop circuit.

Although reference is made herein to an automated spinning operation, noattempt is being made to describe machinery of the aforesaid type indetail. Reference is made, however, to the commonly assigned Bell andNiederer co-pending application Ser. No. 534,081, filed Mar. 14, 1966,for such apparatus. Additionally, as will be apparent, the present yarnsensing device can be employed in automatic winding machinery of thetype described in Goodhue et al., US. Patent No. 2,764,362 issued Sept.25, 1956. The invention is confined to the yarn sensing mechanism andthe method and techniques of adapting the present system to suchmachinery is within the ability of one skilled in the art and does notrequire detailed discussion in the present disclosure.

Having described the improved fluid pressure sensing system in generalterms, reference will be made to the drawing to define the preferredembodiment and to give a more complete explanation of its operation.

The drawing In the drawing FIGURE 1 is a schematic arrangement of thepneumatic sensing system; and

FIGURE 2 is an enlarged detailed view of the yam feeler, vane and airjet and receiver of the unit of FIG- URE 1.

More specifically, a feeler wire 1 is pivotally mounted on a suitableframe, as for example, on a patrolling tender 3 (see FIG. 2) for aspinning machine of the type described in the aforesaid Bell andNiederer application. A vane 4 is associated with the portion of thefeeler wire 1 which extends beyond the pivot point 2. An air jet 5 blowsair into receiver 6 which is delivered through conduit 7 to a fluidpressure transducer 8. The transducer 8 can be of conventional designand comprises a diaphragm means 8.1 in operable association with a stem8.2 which holds contacts 8.3 of a sensor relay together when thetransducer 8 is receiving a supply of air. A second air jet 5.1 and airreceiver 61 is in communication with the transducer 8 through conduitmeans 7.1. A vane 4.1 pivotally mounted upon the patrolling tender 3 at2.1 is constructed and arranged to automatically interrupt the secondair jet 5.1 at each position of the spinning device. Additionally asource of high pressure is in contact with the second surface ofdiaphragm 8.1 of the transducer 8 through a conduit means 7.2. The threeway valve 9 is actuated by a sensor 10 on the patrolling tender 3 whichsenses when bobbin B is full.

In operation of the fluid pressure sensing system according to thepreferred embodiment, the feeler wire 1, the associated vane 4, air jets5 and 5.1, transducer 8 and full bobbin sensor 10 are mounted on thecarriage of the patrolling tender 3. At each spinning position theregistration vane 4.1 drops down and cuts off the air supply from jets5.1 to receiver 6.1 as shown in FIG. 1. However, the contacts 8.3 of thesensor relay are not opened unless the air jet 5 to receiver 6 is alsointerrupted. This air supply is not interrupted unless the yarn strand Yin the spinning position is broken. If the yarn strand Y is broken thefeeler wire 1 will drop as shown by the broken lines in FIGURE 2 causingvane 4 to interrupt the air supply. Since no air is flowing totransducer 8, the transducer will be exhausted, causing diaphragm 8.1 torelax, opening contacts 18.3. The sensor relay will signal the tender tostop and initiate a rethreading operation. In the event the bobbin B atthe spinning position is full and requires doffing, full bobbin sensor10 will actuate the three way valve 9 permitting high pressure to flowto transducer 8. Regardless of whether the air flow from air jets 5 and5.1 to the trans ducer 8 is interrupted, the transducer contacts 8.3will open, signaling the patrolling tender 3 to stop and initiate theservicing operation.

Inasmuch 'as the actual spinning machine and patrolling tender referredto hereinbefore form no part of the present invention, a detaileddescription of the apparatus has not been set forth herein. Furthermore,since the adaptation of the presently described device to the spinningunit of Bell and Niederer can be readily accomplished by one skilled inthe art having the present specification as well as the Bell andNiederer application as a guide, a detailed description of theadaptation is not being set forth herein.

The feeler wire 1 as employed in the present invention can be anymaterial which is relatively light and possesses the necessary strengthpermitting it to be pivotally mounted. The feeler wire 1 isapproximately 3 /2 inches long and 2 /2 inches wide at the point atwhich it contacts the yarn strand Y. The air for the air jets 5 and 5.1can be supplied from any conventional pump. Since the patrolling tender3 is preferably operated by an air motor, it may already be equippedwith a supply of air; The fluid pressure transducer 8 employed, asindicated hereinbefore, can be of conventional design. However, becauseof its exceptional sensitivity, a transducer of the type disclosed incommonly assigned Kent co-pending application Ser. No. 579,664 filedSept. 15, 1966, is preferred. The remaining elements of the constructionare again conventional.

It should be appreciated that the instant invention is not to beconstrued as being limited by the illustrative embodiments. It ispossible to produce still other embodiments without departing from theinventive concept herein disclosed. Such embodiments are within theability of one skilled in the art.

We claim:

1. A pressure sensing system for providing a signal in response to thepresence of a full bobbin comprising a pressure responsive transducer,means for introducing a first pressure to said transducer to urge saidtransducer to an inactive position, sensing means operable to detect afull bobbin, a second pressure, and means operable in response todetection of said full bobbin by said sensing means for presenting saidsecond pressure to said transducer to thereby urge said transducer to anactive position to provide said signal.

2. The combination as set forth in claim 1 wherein said transducerincludes a movable diaphragm, said first pressure is a fluid directedagainst one side of Said diaphragm, and the second pressure is a fluiddirected against the opposite side of said diaphragm.

3. The combination as set forth in claim 2 wherein said second fluidpressure is under a relatively higher pressure than said first fluidpressure.

4. The combination as set forth in claim 1 wherein said system ismounted on a patrolling tender movable relative to at least one yarnprocessing station on an associated textile machine, said sensing meansbeing operable as said tender moves proximate to said bobbin to contactsaid bobbin when full and thereby present said second fluid source tosaid transducer.

5. The combination as set forth in claim 1 wherein said means forintroducing a first pressure to said transducer includes a fluid jet,and a fluid receiver for receiving the fluid from said jet forconductance to said transducer; and interrupting means responsive to theabsence of yarn advancing from a supply source to said bobbin forstopping said first pressure to said transducer, said transducer in theabsence of said first pressure being movable to said active position toprovide said signal.

6. The combination as set forth in claim 5 wherein said system ismounted on a patrolling tender movable relative to at least one yarnprocessing station on an associated textile machine, and including meansfor presenting a third pressure to said transducer to urge saidtransducer to said inactive position, said third pressure to saidtransducer being stopped as said tender moves into a servicing positionat said processing station, said signal being operative to commence aservicing cycle.

7. The combination as set forth in claim 6 wherein said transducerincludes a movable diaphragm, said first and third pressures are fluiddirected against one side of said diaphragm, and said second pressure isa fluid directed against the opposite side of said diaphragm.

8. The combination as set forth in claim 7 wherein said second fluidpressure is under a relatively high pres sure than either one of saidfirst or third pressures.

9. The combination as set forth in claim 8 wherein said first, secondand third pressures are compressed air.

10. The combination as set forth in claim 8 including a pair ofelectrical contacts, and means controlled by movement of said diaphragmfor effecting opening and closing of said contacts; said contacts whenin one of said open and closed positions providing a signal, and when inthe other of said open and closed position being inactive.

6 References Cited UNITED STATES PATENTS 2,077,525 4/1937 Mennesson 57812,900,468 8/1959 Joy 200--61.13 XR 3,159,028 12/1964 Hornbostel 20061.18XR 3,345,475 10/1967 Hope 20061.18 XR STANLEY N. GILREATH, PrimaryExaminer.

W. H. SCHROEDER, Assistant Examiner.

